Cthulhu Now!

[Mr. DNA]

I've recently been tinkering around with an idea for a game of investigative cosmic horror, in which the characteristics of the creature are created during (and through) the investigation process.  The idea is partially based on my initial misunderstanding of what the Gumshoe system was going to be like -- I heard the line about the important part of an investigative game not being the finding of clues but the interpretation of them, and I extrapolated my dream Cthulhu game from that.  Inevitably, the game I had in my mind and the game they had in their book were two different things; which is fine.  Esoterrorists looks way cool anyway, and I'll probably be getting Trail of Cthulhu eventually.  But I like my game idea, too.

Basically, what I took that whole bit about Interpretations to mean was that at the start of the game the GM wouldn't have any better idea than the players exactly what they were up against or how to defeat it.  The GMs job would be to create juicy hooks in the form of somewhat ambiguous clues, and then put them where the characters would find them.  The characters' skills in investigative areas would determine how accurately they could interpret the clues.  (Or at least, the investigative skills PLUS the character's knowledge of the Cthulhu mythos -- someone with no experience battling horrors from beyond isn't likely to guess that they're up against non-Euclidean Horrors from Beyond.)  The skill is rolled in a sort of Hypothosis -> Test -> Result form, where the Hypothosis is the character's interpretation, the Test is the roll, and the Result is whether or not the interpretation becomes fact. 

So, as an example, let's say that the PCs are performing an autopsy on a victim with several deep wounds on his abdomen.  One of the characters, Hubert Cumberdale, decides to see if he can figure out what sort of weapon caused the wounds. So he uses his Forensics skill.  "I think that the wounds were caused by a wickedly shaped dagger," says the player.  The die is cast.  If Hubert succeeds, he is correct in his hypothosis, and the wounds were indeed caused by a ubiquitous dagger of blasphemous aspect.

If he fails, however, the interpretation is left to the GM, who can come up with anything she wants.  Perhaps the wounds were caused, instead, by the horrid teeth of some unnamable beast.  Perhaps they were self inflicted somehow.  Whatever she comes up with is kept unknown to the players for now.  I envision a GM's sheet of facts about the monster, where she keeps a list of the characteristics the players know and don't know about the monster.

In this way, the shape of the monster or perpetrator or cult or conspiracy gradually begins to take shape.  It's my assumption that once a picture has solidified to a certain point in the GM's mind, the clues become more substantial, the enemy becomes more concrete, and eventually -- at some point -- there is a big Reveal, where the Enemy is Unveiled, and madness and chaos generally reign.  Aha!  But by that point, along the way, there needs to have been established some means, some hope however remote, for the players to stave off the horror until another day. 

Obviously this is all really just a kernel of an idea at this point, but I did have a few questions.

First, I'm wondering about Player knowledge vs. Character knowledge.  Should the players be in on the actual data about the enemy, or should the GM's antagonist sheet be kept secret from them as it develops?   And if the players should be kept in the dark, would be better if they didn't know it when they failed a roll somehow?  Ehhh.  Probably not; though I do think part of the fun will be when the Big Reveal happens and the characters are all panicking about the bits they got wrong.

Second, even if the players know when they've failed a roll, should the characters be aware of it?  That is, should a failed roll mean they decide they don't know what the clue means?  Or should they stick to the hypothosis, thinking it's correct?
Perhaps when a character fails a roll, he still gets a clue about the GM's interpretation.  "No, it isn't human blood.  It's something synthetic."  Or perhaps all three are a possibility, contingent on how badly he fails? 

A critical failure -- The character thinks that his hypothosis was correct.
Failure - The character realizes that his hypothosis was incorrect, but the results are inconclusive.
Partial failure - The character realizes that his hypothosis was incorrect, and the results point him in the right direction.

Does that seem reasonable?  Any thoughts?

[chronoplasm]

Ooh. I like.
No, I think you've got it right on the money there.
One suggestion I have for you is maybe giving characters some kind of 'arrogance' or 'jump to conclusions' stat or trait that makes the character more likely to think their hypothesis was correct.

[Vulpinoid]

There have been a couple of suggestions over the past few months regarding similar concepts to this.

I definietly think it's worth pursuing.

Perhaps a checklist of sorts where every successful skill test eliminates some of the possible options.

"We know it uses claws, so if can't be Creature A, B, G, H or L, because they don't have claws. We know that it is capable of striking during the day which rules out creatures C, F, I, J and M. That's limits it to Creatures D, E, K and N. D and K are hydrophobic and two of the attacks occured in a seaside town...it doesn't necessarily rule them out, but it makes them unlikely. How can we differential between creatures E and N?"

Almost like a game of "Guess Who?"

V
 

[Callan S.]

The GMs job would be to create juicy hooks in the form of somewhat ambiguous clues, and then put them where the characters would find them.

Could it also be that the players don't need to find them? That whatever they start focusing on, becomes a clue? Like as GM you just described the bellhop on a whim, but now he's becoming like the center of a massive conspiracy? Perhaps have some small bonus, like a 5% bonus, on clues the GM made, so players do look for them. But when they make a mistake and go after something that isn't a clue, it doesn't matter much system efficiency wise - their mistake will ultimately make a richer, more unexpected game. Just an idea that seems exciting to me

[Mr. DNA]

Thanks for the comments everyone!  I was thinking last night about the other side of the roll, where the investigator succeeds, and came up with this:

Critical Success - The investigator is correct, and gets to add a detail to the Enemy's weakness.
Success - The investigator is correct.
Partial Success - The GM gets to say "Yes, but..." and add some contradictory detail.

One suggestion I have for you is maybe giving characters some kind of 'arrogance' or 'jump to conclusions' stat or trait that
makes the character more likely to think their hypothesis was correct.

Sort of like an opposite to the Cthulhu Mythos skill, perhaps?  I tend to think the dichotomy in Lovecraftian horror is between the way we think the world works (through science and reason and all), and the way it actually works in the stories (the mythos).  So perhaps this stat or trait should measure how attached they are to thinking of the world in the normal way.  I dunno -- maybe what we're describing is good ol' Sanity, just used in a slightly different way?

Could it also be that the players don't need to find them? That whatever they start focusing on, becomes a clue? Like as GM you just described the bellhop on a whim, but now he's becoming like the center of a massive conspiracy? Perhaps have some small bonus, like a 5% bonus, on clues the GM made, so players do look for them. But when they make a mistake and go after something that isn't a clue, it doesn't matter much system efficiency wise - their mistake will ultimately make a richer, more unexpected game. Just an idea that seems exciting to me

Oh, definitely!  That's totally the way to go -- the PCs can think pretty much anything is a clue, and roll for it.  If they fail, of course, the GM can decide whether or not it was legitimately "mythos" or not, and if they succeed, it can be whatever they want it to be.  And even more than that, maybe the players should be able to come up with clues themselves -- "How about, on the ground in the middle of the ruins, we find a broken bit of bone sticking up from the ground?"    "Okay, roll for it."

Perhaps a checklist of sorts where every successful skill test eliminates some of the possible options.  "We know it uses claws, so if can't be Creature A, B, G, H or L, because they don't have claws. We know that it is capable of striking during the day which rules out creatures C, F, I, J and M. That's limits it to Creatures D, E, K and N. D and K are hydrophobic and two of the attacks occured in a seaside town...it doesn't necessarily rule them out, but it makes them unlikely. How can we differential between creatures E and N?"

Almost like a game of "Guess Who?"

I like that idea, but I almost don't want to have pre-created creatures out there.  I think what I'm going for is more the *feel* of the Lovecraft stories, created dynamically, rather than either taking the entities from the established mythos itself, or creating my own mythos for the game.

[chronoplasm]

Hmmm... Maybe instead of ruling out mythos creatures you rule out normal creatures?
"A human being couldn't have possibly done this."
"Whatever did this, it wasn't a gun."
"How does a person get attacked by a shark in the middle of a cornfield?"
Perhaps as players rule out the normal possibilities, you can decrease the 'sanity level' of the game or whatever.
On the other hand, maybe it does turn out that there is a perfectly plausable situation for something? Maybe the wound really was just caused by a knife and not some kind of claw or fang. Then again, maybe the attacker was a Cthulhu cultist and the game can shift toward the paranormal from there?
It'd be like... players decide how wierd they want the game to get, and how quickly.

[apeiron]

So, is the player making this deduction based on what the GM describes, or is it whatever the player makes up?  If it is the latter, you'd need a mechanism for keeping the player from making up something wacky or that would take the players far from where they ought to be headed.  The GM might have meant for it be the result of a demon impaling someone with a wavy horn.  If the player decides it was a wavy dagger and is "right", the GM has to either get them back to looking for a demon, or make up a bunch of new material about guys with wavy daggers.

[Mr. DNA]

So, is the player making this deduction based on what the GM describes, or is it whatever the player makes up?  If it is the latter, you'd need a mechanism for keeping the player from making up something wacky or that would take the players far from where they ought to be headed.  The GM might have meant for it be the result of a demon impaling someone with a wavy horn.  If the player decides it was a wavy dagger and is "right", the GM has to either get them back to looking for a demon, or make up a bunch of new material about guys with wavy daggers.

I think we will need some sort of mechanical encouragement to stay in-genre; I'll have to think about that one.  But I'm perfectly fine with the GM thinking it's a demon and the player deciding it's a knife.  I really don't want the GM to come into the game with a full adventure written out -- he has maybe an idea for framing the first scene, and then it's a collaboration between the mechanics, the players' ideas and the GM's ideas.   For example, to take the dagger/demon idea, let's say the PC investigating the wound decides that it is a knife.

GM: There are several wounds on the corpse's torso, ugly slashing cuts.
Player 1: I'm going to roll my Autopsy skill to determine the cause.  I bet it was a knife of some sort; probably a result of some occult activity.
GM: Okay, go ahead and roll.
Player 1: (rolls and succeeds) It looks like the wounds were caused by a cruelly-shaped dagger, crooked and spiked.
GM: (Writes this down on his sheet, along with, in big letters: HUMAN INVOLVEMENT.  Because we know now that it's not just some creature out there mauling people).  Okay.  What are the rest of you doing?
Player 2: I'm examining the broken window, trying to find anything the perpetrator might have left behind.  Since we know it was a knife wound, I'm guessing there's going to be some threads of cloth, maybe, that got ripped as the killer leapt through the window.  Maybe they're from ceremonial robes of some sort.
GM: Roll your Crime Scene Investigation skill.
Player 2: (rolls and gets a partial success: the GM will be able to affix some detail or another to the end of the statement.)  Okay, so I do find some threads...
GM: ...But you also find something you weren't expecting: a black, inky goo of some sort.  (The GM writes down on his sheet: Black Gooey Substance).
Player 2: Goodness!  I'll have to analyse that back at the lab.  I try to collect a sample of it without any getting on my skin or clothes.
GM: Okay, I think you can manage that pretty easily.  You slip it and the threads into seperate plastic bags.  Now, what about you, (Player 3)?
Player 3: I'm still at the library, trying to find out more about the name fragment we found earlier.  Csdg...something.  The rest was illegible.
Player 2: Not that Csdg is all that legible either.
Player 3: Right.  Anyway, if I succeed I think that this Csdg thingy should be the name of the god of the cult the others are investigating.
GM: Okay, sounds good.
Player 3: (Rolls Library skill, and fails.)  Crap!  Inconclusive.
GM: Hmmmm...interesting.  (He notes on his sheet: Csdg....  = metamorphic victim.)


...Which brings me to another subject, and that is, what happens when a PC fails an investigation roll?  Specifically, what happens with the information that the GM gets to add to the Antagonist sheet?  The issue here is that if the players don't know about it, they can't take it into account when adding facts, and so it's completely possible to contradict it.  If the name from the above example comes up in another investigation, it's likely that one of the other players will come up with something that makes it back into the god of the cult, or something else entirely.  A couple ideas:

1. At that point, the GM can just tell them, "No, your findings don't point to that conclusion", and perhaps give them a clue in the right direction.
2. When a roll fails, the GM gets some sort of point-token resource that allows them to change the results of a later roll, or to change a player's hypothosis.
3. The GM is free to bring his facts into the game at any point, so long as it isn't preemptively contradicted by a PC guess.
So, in the above example, maybe Player 2 is heading for the Lab to investigate the black goo, and is attacked by a half-man, half-...you know, something else, that bleeds black goo when hit.  Maybe the GM must bring his facts in at the very next scene? Or maybe he can hold onto it for later.

[NN]

What if there is a "Reputation" (there must be a better term!) resource that describes the trouble you are in in the mundane world.  Run out of Reputation and you get arrested and thrown in prison or an asylum.

Failed investigations will lead to a new scene, with a chance for success, but at the cost of Reputation.

Maybe high Reputation helps with certain kinds of conflicts (at the dinner party, trying to get Captain Briggs to reveal exactly what he saw on the ill-fated expedtion up the Congo), low Rep with others (stealing that car so you can get to the Summoning in time to prevent it)

Nick

[Nathaniel]

Basically, what I took that whole bit about Interpretations to mean was that at the start of the game the GM wouldn't have any better idea than the players exactly what they were up against or how to defeat it.  The GMs job would be to create juicy hooks in the form of somewhat ambiguous clues, and then put them where the characters would find them.  The characters' skills in investigative areas would determine how accurately they could interpret the clues.  (Or at least, the investigative skills PLUS the character's knowledge of the Cthulhu mythos -- someone with no experience battling horrors from beyond isn't likely to guess that they're up against non-Euclidean Horrors from Beyond.)

Isn't this a good place to integrate player knowledge rather than have it solely rely on character skill + character knowledge?  If the players are in the game and are buying into the idea of creating the details of the yog-sothotian threat, then perhaps the players can have input that's sort of a "it's more than you know" moment to their own characters.

If he fails, however, the interpretation is left to the GM, who can come up with anything she wants.

Perhaps there can be something in the dice to guide the narration regardless of who wins the right to interpret the roll?  For example, perhaps some other dice are rolled along with the check and it produce different results:  the monster itself, the monster's followers, a person driven mad by the monster, etc.,.  So the roll comes up a failure and "a person driven mad by the monster."  The GM notes to himself that Old Conrad the grounds keeper has completely lost it and killed the man with a pitchfork.  The players are let know that the wounds look like a pitch fork or some sort of gardening tool.  So at this point, they know it was a person driven mad by the monster (they can see the dice) and something to do with gardening.

Whatever she comes up with is kept unknown to the players for now.  I envision a GM's sheet of facts about the monster, where she keeps a list of the characteristics the players know and don't know about the monster.

I think the GM should drive play towards the unveiled facts becoming discovered.  Whether it takes Old Conrad killing another one of those who have become tainted by the other, or even just something to remind them that there was a gardener working for the victim.  Intergating Old Conrad before he's locked away in an asylum for the criminally insane would probably add some new characteristics of the monster (he saw it, after all).

It's my assumption that once a picture has solidified to a certain point in the GM's mind, the clues become more substantial, the enemy becomes more concrete, and eventually -- at some point -- there is a big Reveal, where the Enemy is Unveiled, and madness and chaos generally reign.  Aha!  But by that point, along the way, there needs to have been established some means, some hope however remote, for the players to stave off the horror until another day. 

So there might need to be a mechanic to let the GM know that the time for the reveal is at hand.  Some sort of characteristic revealed has to be a way to stop it, a weakness, etc.,.

First, I'm wondering about Player knowledge vs. Character knowledge.  Should the players be in on the actual data about the enemy, or should the GM's antagonist sheet be kept secret from them as it develops?   And if the players should be kept in the dark, would be better if they didn't know it when they failed a roll somehow?  Ehhh.  Probably not; though I do think part of the fun will be when the Big Reveal happens and the characters are all panicking about the bits they got wrong.

I think a composite system would work.  Where the players might know general things about the monster when they fail, even if their character doesn't.

The direction dice that let you know how to narrate could change based on how the question is asked.

Who did a specific act:  Monster, Willing human, Unwilling human (is there any other answer that is still interesting to the story?)
Physical characteristic about the monster: Tangible, Intangible, Behavior
Motives, goal or plan of the monster (and it's minions): Cosmic, Physical, Communal

Monster -- the monster itself did the act in question
Willing human -- a willing follower of the monster (despite how ignorant they themselves are of the nature of the monster) did the act in question
Unwilling human -- someone does it either out of insanity or mind control or even blackmail or something

Tangible -- some physical characteristic about the monster "oooh.... those 6 eyes... like fire... like fire..."
Intangible -- some consistent feeling experienced by those who get too close "my blood boiled.  I remember getting so angry with Doris.  She was supposed to pick up the kids yesterday and I had to do it.  Go out of my way.  I don't know quite what happened but in that moment I wanted nothing more than to strangle her.  And... sob... little Jesse too... tell me I didn't... tell me I didn't..."
Behavior -- something the monster does.  "After analyzing the bones, you're quite convinced the substance found on them was digestive fluid.  Something ate these bones.  Something ate these bones whole."

Cosmic -- Summoning an elder god, waking the Great Old One Cthulhu.  Something big that will not be good for humanity.  So a single clue might be that there's something ritualistic going on.  Further investigation might reveal another clue about the exact nature of what the purpose of the ritual is.  If previous roles were physical or communal, the insight would then be how those physical or communal goals are fitting with the overall cosmic goal.
Physical  -- the monster might be pursuing alien goals, but it's accomplished through physical means.  Perhaps it needs to feed on 100 bodies so it can go into another hibernation cycle.  Perhaps the "monster" is a human sorcerer who is trying to accomplish some personal physical aim, like getting lots of money to fund further research.  Or something physical that must be accomplished to get the overall plan moving forward.  Getting a certain ancient idol, a certain book, etc.,.
Communal -- the setting up of a following, dynasty, family.  Like Deep Ones wanting to capture human men & women to mate with humankind.  A monster developing a cult to do it's bidding.  Or perhaps a cult growing to gain power (be it to get something physical or something cosmic as revealed by other rolls).  Or the stark absence of such goals.  Whatever the statement is, it's about how the monster/minions are planning regarding other people.  And a communal result, perhaps the characters learn that the cultists don't get it and are not part of the monster's plan and are just dupes.

I find that when the dice just determine who gets to narrate but with no guidance as to what that narration should contain or how it should slant, things can fall a bit flat.

I don't know.  Just brainstorming.

[apeiron]

OK, i think i got it.

So, the GM should describe events in a way that give clues (and maybe a red herring) to the players.  Then the player's assumptions or role-playing interpret that (which is very realistic, there is no reality, only perception).  The GM can then either steer them or riff off the player. 

Lovely. 

Metagaming is always a possibility, to that i offer "Challenge!"

Dave, there is no way your character would think that!

Um well, he's got X ranks in Whatsitmancy.  Remember last month when event X lead in direction Y with outcome Z?

Oh, yeah, OK, go on then.  You clever bastard.

OR

Bull-oney! I'm going to give you a penalty on your roll for that. 

[Alfryd]

Sort of like an opposite to the Cthulhu Mythos skill, perhaps?

Yeah, sort of.  Increases maximum sanity through confidence and daring, but makes erroneous conclusions more likely.

Oh, definitely!  That's totally the way to go -- the PCs can think pretty much anything is a clue, and roll for it.  If they fail, of course, the GM can decide whether or not it was legitimately "mythos" or not, and if they succeed, it can be whatever they want it to be.  And even more than that, maybe the players should be able to come up with clues themselves -- "How about, on the ground in the middle of the ruins, we find a broken bit of bone sticking up from the ground?"    "Okay, roll for it."

We've been having a prolongued dicussion on the merits and pitfalls of the approach in this thread.  There is a general danger with any system where the players establish the world as they go- either subtle inconsistencies may creep in that you can't easily retcon, or the players options become more and more constrained by prior events.  In your case, the list of previous clues will wind up limiting the conclusions that players can draw without contradicting themselves.

I like that idea, but I almost don't want to have pre-created creatures out there.  I think what I'm going for is more the *feel* of the Lovecraft stories, created dynamically, rather than either taking the entities from the established mythos itself, or creating my own mythos for the game.

Okay.  But how do you intend to terminate the process of investigation, if there's no 'finished product' you can identify by a process of elimination?

[Mr. DNA]

Sorry, got busy with work so I haven't had a chance to think on this much lately.

Nathaniel makes some good points.

Isn't this a good place to integrate player knowledge rather than have it solely rely on character skill + character knowledge?  If the players are in the game and are buying into the idea of creating the details of the yog-sothotian threat, then perhaps the players can have input that's sort of a "it's more than you know" moment to their own characters.

If I understand you correctly, you're saying that a player's ability to interpret the clue shouldn't necessarily be tied to their character actually coming to the correct conclusion?  I can definitely see the possibility for some added drama there.  In fact, integrating your thoughts here in some way would solve my qualms with keeping the monster sheet out of sight in general -- we just wouldn't.  Which I like much, much better anyway.  So the player can see the antagonist sheet, and knows where the character has gotten it wrong -- excellent.  Hmmmm....perhaps something like with Prime Time Adventures, where the player with the most points wins the conflict, but the player with the highest card overall gets the narration authority. 

So, let's say that the mechanic is dice-pool based.  When a conflict comes up,  the characters roll for it with thier dice pools, add their highest two dice, and whoever has the highest sum wins.  If a character wins, their hypothosis is correct; if they fail, they get it wrong.  Either way, whoever has the highest single die gets to write down a fact on the Antagonist sheet.  Something like that.

The direction dice that let you know how to narrate could change based on how the question is asked.

Who did a specific act:  Monster, Willing human, Unwilling human (is there any other answer that is still interesting to the story?)
Physical characteristic about the monster: Tangible, Intangible, Behavior
Motives, goal or plan of the monster (and it's minions): Cosmic, Physical, Communal

Monster -- the monster itself did the act in question
Willing human -- a willing follower of the monster (despite how ignorant they themselves are of the nature of the monster) did the act in question
Unwilling human -- someone does it either out of insanity or mind control or even blackmail or something

Tangible -- some physical characteristic about the monster "oooh.... those 6 eyes... like fire... like fire..."
Intangible -- some consistent feeling experienced by those who get too close "my blood boiled.  I remember getting so angry with Doris.  She was supposed to pick up the kids yesterday and I had to do it.  Go out of my way.  I don't know quite what happened but in that moment I wanted nothing more than to strangle her.  And... sob... little Jesse too... tell me I didn't... tell me I didn't..."
Behavior -- something the monster does.  "After analyzing the bones, you're quite convinced the substance found on them was digestive fluid.  Something ate these bones.

Sort of like an opposite to the Cthulhu Mythos skill, perhaps?

Yeah, sort of.  Increases maximum sanity through confidence and daring, but makes erroneous conclusions more likely.

Oh, definitely!  That's totally the way to go -- the PCs can think pretty much anything is a clue, and roll for it.  If they fail, of course, the GM can decide whether or not it was legitimately "mythos" or not, and if they succeed, it can be whatever they want it to be.  And even more than that, maybe the players should be able to come up with clues themselves -- "How about, on the ground in the middle of the ruins, we find a broken bit of bone sticking up from the ground?"    "Okay, roll for it."

We've been having a prolongued dicussion on the merits and pitfalls of the approach in this thread.  There is a general danger with any system where the players establish the world as they go- either subtle inconsistencies may creep in that you can't easily retcon, or the players options become more and more constrained by prior events.  In your case, the list of previous clues will wind up limiting the conclusions that players can draw without contradicting themselves.

I like that idea, but I almost don't want to have pre-created creatures out there.  I think what I'm going for is more the *feel* of the Lovecraft stories, created dynamically, rather than either taking the entities from the established mythos itself, or creating my own mythos for the game.

Okay.  But how do you intend to terminate the process of investigation, if there's no 'finished product' you can identify by a process of elimination?

Something ate these bones whole."

Cosmic -- Summoning an elder god, waking the Great Old One Cthulhu.  Something big that will not be good for humanity.  So a single clue might be that there's something ritualistic going on.  Further investigation might reveal another clue about the exact nature of what the purpose of the ritual is.  If previous roles were physical or communal, the insight would then be how those physical or communal goals are fitting with the overall cosmic goal.
Physical  -- the monster might be pursuing alien goals, but it's accomplished through physical means.  Perhaps it needs to feed on 100 bodies so it can go into another hibernation cycle.  Perhaps the "monster" is a human sorcerer who is trying to accomplish some personal physical aim, like getting lots of money to fund further research.  Or something physical that must be accomplished to get the overall plan moving forward.  Getting a certain ancient idol, a certain book, etc.,.
Communal -- the setting up of a following, dynasty, family.  Like Deep Ones wanting to capture human men & women to mate with humankind.  A monster developing a cult to do it's bidding.  Or perhaps a cult growing to gain power (be it to get something physical or something cosmic as revealed by other rolls).  Or the stark absence of such goals.  Whatever the statement is, it's about how the monster/minions are planning regarding other people.  And a communal result, perhaps the characters learn that the cultists don't get it and are not part of the monster's plan and are just dupes.

I find that when the dice just determine who gets to narrate but with no guidance as to what that narration should contain or how it should slant, things can fall a bit flat.

I don't know.  Just brainstorming.

All of those are great: I think they all belong on the Antagonist sheet.

In your case, the list of previous clues will wind up limiting the conclusions that players can draw without contradicting themselves.

Wow, that's an interesting link and good food for thought.  Thanks!  But to answer your question, it does indeed seem that as the game progresses, the players will have an increasingly narrow range of conclusions to draw.  But that's as it should be, isn't it?  As the creature becomes more solidified, the investigators will be closer to the end of their investigation.  Of course, if we split the player/investigator knowledge (as above), the investigators may have to rethink their previous conclusions when contradicting information comes up: if this bogs the game down, we may need to ditch the separation of knowledge or find an alternative.
But it does seem like this constant narrowing would go a ways towards answer your second question,

But how do you intend to terminate the process of investigation, if there's no 'finished product' you can identify by a process of elimination?

Here's what I've been thinking: Let's say the antagonist sheet has a number of elements on it similar to the ones that Nathaniel mentioned above, and that the player conclusions fill in the different elements.  A scrap of name here, a method of killing there.  Is it a cult of an Elder God, or is it a simple Fish-Man?  The investigation is over when the players fill in the elements.  Or, perhaps there could be a reason to end the investigation before all the pieces are together; if, say, there's a countdown to doomsday, or the creature strikes before the players are ready.

So what happens if there are elements left to consider when the characters confront the Antagonist?  That may require some thought.

[apeiron]

May i introduce you to The Burning Wheel?

It works just like what you are describing.

[Mr. DNA]

Apeiron,

Do you mean mechanically, the dice pool thing, or investigatively, the antagonist sheet thing, or something else entirely?